Presents genetical and biochemical data to show that the conclusion presented by Dyer (EJ 036 108) is by no meas settled. Evidence to support the concept: evolution by selectively neutral polymorphisms is inconclusive. (AL)

The effects of impeller size, agitation and aeration on the rate of yeast growth were investigated using bench-top bioreactors. This exercise, carried out over a six-month period, served as an effective demonstration of the importance of different operating parameters on cell growth and provided a means of determining the optimisation conditions…

Updates knowledge on nitrogen fixation, indicating that investigation of free-living nitrogen-fixing organisms is proving useful in understanding bacterial partners and is expected to lead to development of more effective symbioses. Specific areas considered include biochemistry/genetics, synthesis control, proteins and enzymes, symbiotic systems,…

Two investigations are reported regarding grasshoppers and their behavior. Procedures and data are included and materials for further work are available. (PS)

Describes the hazards of using living materials in the science laboratory and outlines safety procedures that are particularly applicable to schools. Explains hazards to both mental and physical health and examines the latter in terms of fundamental and contingent factors. (Author/GS)

The use of green, red, and far-red light-emitting diodes (LEDs) as light sources for plant physiological studies is outlined and evaluated. Indicates that LED lamps have the advantage over conventional light sources in that they are lightweight, low-cost, portable, easily constructed, and do not require color filters. (Author/DH)

Describes techniques and results of a study on leaves of a leguminous tree. (PS)

Reviews steps and procedures for planning, conducting, and presenting basic research. A sample problem is reviewed, step by step, in detail, and three useful research tools are offered. (SL)

Actin and myosin have now been demonstrated to be important constituents of many eukaryotic cells. Their role is primarily that of a contractile system underlying all aspects of cellular motility. Described here is a simple experimental system to demonstrate quantitatively aspects of motility and its regulation in a slime mold. (Author/MA)

Summarizes current information on the structure and function of cilia. Three types of experiments are suggested using paramecium to investigate aspects of ciliate behavior. (Author/DC)

Describes a self-instructional game which simulates scientific research in bacterial genetics. (CS)